Polyclonal Antibodies from Hen Egg Yolk (IgY) with Hydrolysis Activity

Polyclonal catalytic antibodies (abzymes) play an important role in immunology research. In this study, we report polyclonal antibodies IgYs isolated from chicken egg yolk with hydrolysis activity for the first time. The IgYs were raised in hens using HNPBV [4-(hydroxy (naphthalen-2-yloxy) phosphoryl) butanoic acid] attached to BSA (Bovine serum albumin) as an immunogen. Anti-(HNPBV-BSA) IgYs were isolated from yolks of the eggs laid using a two-step salt precipitation and one-step gel filtration protocol. NA (naphthalen-2-yl acetate) was selected as the substrate and the hydrolysis reaction of the IgYs for it was examined. The result reveals that the rate of the hydrolysis reaction is higher (K _cat/K _uncat∼2 × 10⁴). The purified IgYs were digested with pepsin and the smaller fragment (Fab′) with specific antigen binding properties was produced. The research indicates that the enzymatic properties of Fab′ are similar to IgYs. The catalytic activity of the IgYs was further determined by measuring the rate of hydrolysis of NA in the presence of inhibitor. These findings show that chicken egg is an excellent donor for polyclonal catalytic antibodies.